<nav class="navbar navbar-inverse navbar-fixed-top">
    <div class="container-fluid">
      <div class="navbar-header">
        <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false" aria-controls="navbar">
          <span class="sr-only">Toggle navigation</span>
          <span class="icon-bar"></span>
          <span class="icon-bar"></span>
          <span class="icon-bar"></span>
        </button>
        <a class="navbar-brand" href="#">通讯录</a>
      </div>
      <div id="navbar" class="navbar-collapse collapse">
        <ul class="nav navbar-nav navbar-right">
          <li><a href="#">{{user.email}}</a></li>
          <li><a href="javascript:;" (click) = "siginout()">退出</a></li>
        </ul>
        <!-- <form class="navbar-form navbar-right">
          <input type="text" class="form-control" placeholder="Search...">
        </form> -->
      </div>
    </div>
  </nav>
